The association between hematocrit level and future hospitalization risks i
n hemodialysis patients has not been fully investigated on a national level
. A total of 71,717 prevalent Medicare hemodialysis patients who survived a
6-mo entry period from July 1 through December 31, 1993 were studied, and
their risk of hospitalizations was evaluated the next year. Five hematocrit
groups were defined from Medicare recombinant human erythropoietin-treated
patients: <27%, 27 to <30%, 30 to <33%, 33 to <36%, and greater than or eq
ual to 36%. A Cox regression model was used to investigate the association
between hematocrit level and the risk of first hospitalization, and the And
ersen-Gill regression model evaluated multiple hospitalizations during the
next year, adjusting for patient comorbidity and severity of disease. Compa
red with the baseline group of 30 to <33%, patients with hematocrit levels
<30% had a 14 to 30% increased risk of hospitalization without disease seve
rity adjustment (p = 0.0001) and a 7 to 18% increased risk with disease sev
erity adjustment (p = 0.0001). Patients in the 33 to <36% group had the low
est risk at 0.93 and 0.88 (p = 0.0001), with and without adjustment for dis
ease severity. It is concluded that patients with hematocrits of <30% have
an increased risk of future hospitalization, with hematocrit levels between
33 and 36% having the lowest associated risks.